Science is a method for catching our own mistakes, not a list of facts

Sagan's central reframing is that science should be understood primarily as a way of thinking rather than a body of established conclusions — a disciplined process of proposing explanations, then actively trying to disprove them, that works precisely because it assumes the investigator, including the scientist, is capable of being wrong.

He contrasts this humility with the confident certainty of pseudoscience, which typically starts from a desired conclusion and works backward to find supporting anecdotes, rather than starting from evidence and letting it lead wherever it leads, even somewhere unwelcome.

Sagan calls this discipline self-correction, and argues it's the single feature that separates science from every other belief system humans have devised — not that scientists are smarter or more virtuous, but that the method itself is built to catch errors that individual bias would otherwise let slide. Takeaway: judge a claim not by how confident its proponent sounds, but by whether the claim's method allows for being proven wrong.